编写安卓应用启动界面Splash 详解Android中App的启动界面Splash的编写方法
时光微凉 人气:0一、Splash界面的作用
用来展现产品的Logo
应用程序初始化的操作
检查应用程序的版本
检查当前应用程序是否合法注册
二、界面的xml定义
写一个布局背景设置为产品的logo图片,再添加一个textview显示版本号。
<TextView android:id="@+id/tv_splash_version" android:layout_width="wrap_content" android:layout_height="wrap_content" android:textColor="#000000" android:textStyle="bold" android:shadowDx="1"//阴影的偏移量 android:shadowDy="1" android:shadowRadius="0.2"//阴影的半径 android:shadowColor="#ffff00" android:text="版本:1.0" android:textSize="16sp" android:layout_centerInParent="true"/>
三、动态获取版本号的方法
public String getAppVersion(){ PackageManager pm = getPackageManager(); try { PackageInfo info = pm.getPackageInfo(getPackageName(), 0); return info.versionName; } catch (NameNotFoundException e) { e.printStackTrace(); //不可能发生; return ""; } }
四、链接服务器获取更新信息
升级提醒的对话框
protected void showUpdateDialog() { AlertDialog.Builder build = new Builder(this); build.setTitle("发现新版本"); build.setMessage(description); build.setNegativeButton("立刻升级", new OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { //升级的代码; }; }); build.setPositiveButton("下次再说", new OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { dialog.dismiss(); enterHome(); } }); build.show();
在子线程中请求服务器的代码 checkup()方法
private void checkup() { new Thread() { public void run() { Message msg = Message.obtain(); long startTime = System.currentTimeMillis();//启动该线程的系统时间 try { //请求网络的代码 URL url = new URL(getString(R.string.serverurl)); HttpURLConnection conn = (HttpURLConnection) url .openConnection(); conn.setRequestMethod("GET");//请求方法 conn.setConnectTimeout(4000);//超时时间 int code = conn.getResponseCode();//返回码200请求成功 if (code == 200) { InputStream is = conn.getInputStream(); String result = StreamTools.readFromStream(is); Log.i(TAG, "联网成功" + result); JSONObject obj = new JSONObject(result);//解析json字符串 String version = (String) obj.get("version");//版本信息 description = (String) obj.get("description");//描述信息 apkurl = (String) obj.get("apkurl"); if (getAppVersion().equals(version)) { msg.what = ENTER_HOME; } else { msg.what = SHOW_UPDATE_DIALOG; } } } catch (MalformedURLException e) { e.printStackTrace(); msg.what = URL_ERROR; } catch (IOException e) { e.printStackTrace(); msg.what = NETWORK_ERROR; } catch (JSONException e) { e.printStackTrace(); msg.what = JSON_ERROR; } finally { handler.sendMessage(msg); long endTime = System.currentTimeMillis();//该线程执行完毕的时间 long dTime = endTime-startTime;//该线程的阻塞时间 if (dTime<3000) { try { Thread.sleep(3000-dTime);//若该线程的阻塞时间小于三秒继续睡眠到三秒 } catch (InterruptedException e) { e.printStackTrace(); } } } } }.start(); } handler private Handler handler = new Handler() { @Override public void handleMessage(Message msg) { // TODO Auto-generated method stub super.handleMessage(msg); switch (msg.what) { case SHOW_UPDATE_DIALOG: showUpdateDialog(); break; case ENTER_HOME: Toast.makeText(getApplicationContext(), "", 0).show(); enterhome(); break; case URL_ERROR: Toast.makeText(getApplicationContext(), "URL_ERROR", 0).show(); enterhome(); break; case NETWORK_ERROR: Toast.makeText(getApplicationContext(), "NETWORK_ERROR", 0).show(); enterhome(); break; case JSON_ERROR: Toast.makeText(getApplicationContext(), "JSON_ERROR", 0).show(); enterhome(); break; } } };
五、下载文件(使用Afinal框架)并调用系统安装工具安装APK
if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) { FinalHttp finalHttp = new FinalHttp(); finalHttp.download(apkurl,Environment.getExternalStorageDirectory().getAbsolutePath()+ "/mobilesafe2.0.apk" , new AjaxCallBack<File>() { @Override public void onLoading(long count, long current) { super.onLoading(count, current); tv_uapdate_info.setVisibility(View.VISIBLE); int progress =(int) (current*100/count); tv_uapdate_info.setText("下载进度:"+progress+"%"); } @Override public void onFailure(Throwable t, int errorNo, String strMsg) { t.printStackTrace(); Toast.makeText(getApplicationContext(), "下载失败", 0).show(); enterhome(); super.onFailure(t, errorNo, strMsg); } @Override public void onSuccess(File t) { super.onSuccess(t); installAPK(t); } private void installAPK(File t) { Intent intent = new Intent();//自动安装程序可调用该段代码 intent.setAction("android.intent.action.VIEW"); intent.addCategory("android.intent.category.DEFAULT"); intent.setDataAndType(Uri.fromFile(t), "application/vnd.android.package-archive"); startActivity(intent); } }); }else{ Toast.makeText(getApplicationContext(), "请插入内存卡再试",0).show(); return; }
其他:
1、显示4.0的样式:方式是去掉功能清单里的Activity对应的android:theme;
放到application里面;
2、当splash页面弹出升级提示框过滤点击返回的是两种方式:
builder.setCancelable(false);
设置setOnCancelListener 当触屏的时候直接进入主页面
对话框是挂载在Activity上面的,如果Activity不存在,对话框就不能被创建。
getApplicationContext();生命周期长,只要应用还存活它就存在;this 生命周期短,只要Activity不存在了,系统就会回收
其中:getBaseContext(),getApplication(),getApplicationContext(); 都不能放在AlertDialog做上下文;
3.Splash用来宣传和隐藏程序启动细节是很有用的。
用Handler的实现方法如下:(也可以用线程实现,不推荐)
定义一个Activity,用来显示你的图片,其中最重要的就是定义一个Handler,用来发送和接收消息:
public class WelcomeActivity extends Activity { //定义一个handler,用来接收延迟发送的信息-启动activity private Handler handler = new Handler() { @Override <span style="color: #ff0000;">public void handleMessage(Message msg) </span> { // TODO Auto-generated method stub super.handleMessage(msg); switch(msg.what) { case 0x123: Intent intent = new Intent(WelcomeActivity.this, OnlineExamActivity.class); startActivity(intent); finish(); } } };
在onCreate()方法中,用handler发送消息,延迟3000毫秒:
@Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); setContentView(R.layout.welcome_activity); start(); } private void start() { <span style="color: #ff0000;">handler.sendEmptyMessageDelayed(0x123, 3000);</span> }
把你的图片放到布局文件中作背景即可。
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